Since there has been some questions about the differences in rear axles, and since I have all 3, I decided it was time to measure the differences.

The 96 F350 2wd crewcab dually measured
end of axle tube to end of axle tube 61.5"
end of axle tube to center of spring perch 8"
center to center of spring perch 45.5"

The 96 F350 cab and chasis 4x4
end of axle tube to end of axle tube 55"
end of axle tube to center of spring perch 7.5"
center to center of spring perch 41"

The 97 single rear wheel F350
end of axle tube to end of axle tube 57.5"
end of axle tube to center of spring perch 6"
center to center of spring perch 45.5"

I hope this will help anyone who is looking to convert to duals or replacing a rear axle.

EDIT The end to end of axle tube measurement should be to where the brake backing plate bolts on to the axle housing, not the end of the spindle tubes.

 

Good info Tom! I knew they were all different, but never had the opportunity to measure all three. Thanks bud!

 

Ya, thanks Tom. Good information that I have now saved.

 

I would like to convert mine to duals as well, but was wondering if I need to replace any other components that may not handle the load when I go up to the 350 springs and components. My truck is a 97 F-250 single rear wheel crew cab. I will probably do this at the same time as changing out the front axle. I am probably going to get away from the 4.10 gears as my mpg sucks

 

The 97 f250 HD (which you have) is pretty much the same as a srw F350. The only differences that I can think of is the 250 has the D50, and the 2 inch spacer block between the springs and the rear axle, where as the F350 has the D60 front, with a 4 inch block in the rear. This is of course on the 4X4 models. You will have to get the 4X4 dually hubs for the front if you want all the wheels to be the same. When you swap out the front axle, use the 350 front springs, as the ride won't quite as harsh as if it would be if the stiffer D50 springs would be, and it is a direct swap.

 

Thank You sir!